1. Field of the Disclosure
The present disclosure relates generally to a multi-purpose fill and circulate tool (“FAC tool”) for use in wells, and more specifically, to a FAC tool comprising a packing element system for use during high pressure events.
2. Description of the Related Art
The process of drilling subterranean wells to recover oil and gas from hydrocarbon reservoirs includes drilling a hole in the earth down to the petroleum accumulation and installing pipe from the reservoir to the surface. A casing is used as a protective pipe liner within the wellbore. The casing can be run into the well bore one section at a time. On occasion, the casing becomes stuck and is unable to be lowered into the wellbore. When this occurs, it is common practice to increase the load on the casing string to force the casing into the wellbore, or drilling fluid can be circulated down the inside diameter of the casing and out of the casing into the annulus in order to free the casing from the wellbore. To accomplish this, it has traditionally been the case that special rigging be installed to add axial load to the casing string and/or to facilitate circulating the drilling fluid. For example, a top drive unit that can apply both torque and mechanical load can be employed to force the casing into the wellbore.
When running casing, drilling fluid is generally added to each section as it is run into the well. This procedure is performed to prevent the casing from collapsing due to high pressures within the wellbore. The drilling fluid can also act as a lubricant to facilitate lowering the casing within the wellbore. The drilling fluid is often circulated in the casing and well bore when resistance is experienced as the casing is lowered into the wellbore. In order to circulate the drilling fluid, the top of the casing is sealed so that the casing may be pressurized.
It is well known in the art to employ a FAC tool to seal the top of the casing when adding the drilling fluid to the wellbore. The FAC tool is inserted into the top of the casing as it is run into the well. A top drive unit connects to the top end of the FAC tool and is used to drive the FAC tool and casing into the well. Drilling fluid, such as drilling mud, is injected into the well casing through an axial flowpath in the FAC tool. The FAC tool generally includes packing elements, such as a packer cup, which provides a low pressure seal between the FAC tool and the casing. This can prevent or at least reduce the amount of drilling fluid that is spilled from the top of the casing, and allows the casing to be pressurized to circulate the drilling fluid.
During the running of the casing into the wellbore, pressures experienced by the FAC tool are generally relatively low, (e.g., less than about 1000 psi). However, periodically well pressures can increase to over 1000 psi, such as 5,000 psi or more. When this occurs, the high pressure on the FAC tool is too great for the low pressure seal, and may cause excessive leakage of the drilling fluid from the wellbore, which can be costly and harmful to both the environment and to well rig operators. In some cases a high pressure event can push the FAC tool right out of the wellbore, potentially causing damage to the FAC tool or drilling rig or harm to the drill rig operators.
When a high pressure event is sensed, the well rig operators will generally follow a set of safety protocols that can reduce the risk of harm caused by the event. However, the amount of time between when the high pressure event is sensed and the point at which the packer cup on the FAC tool fails can be relatively short. In some cases, well operators may not have sufficient time to carry out the appropriate safety protocols before damage occurs.
The present disclosure is directed to overcoming, or at least reducing the effects of one or more of the issues set forth above.